[llvm] [LoopFusion] Extending SIV to handle separate loops (PR #146383)

[via llvm-commits]

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@@ -0,0 +1,187 @@
+; RUN: opt -S -passes=loop-fusion -da-disable-delinearization-checks < %s | FileCheck %s
+
+; The two inner loops have no dependency and are allowed to be fused as in the
+; outer loops, different levels are accessed to.
+
+; C Code
+;
+;;  for (long int i = 0; i < n; i++) {
+;;    for (long int j = 0; j < n; j++) {
+;;      for (long int k = 0; k < n; k++)
+;;        A[i][j][k] = i;
+;;      for (long int k = 0; k < n; k++)
+;;        temp = A[i + 3][j + 2][k + 1];
+;;    }
+;;  }
+
+define void @backward_dep0(i64 %n, ptr %A) nounwind uwtable ssp {
+entry:
+  %cmp10 = icmp sgt i64 %n, 0
+  br i1 %cmp10, label %for.cond1.preheader.preheader, label %for.end26
+
+; CHECK-LABEL: backward_dep
+; CHECK-COUNT-1: for.body{{[0-9]+}}:
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CongzheUalberta wrote:

I suggest to not rely on BB names in `CHECK`. You can check `stats`, like how many functions are fused, how many dependence checks are passed, etc.

https://github.com/llvm/llvm-project/pull/146383